Breeding of high yield xylanase chaetomium globosum protoplast by ultraviolet mutation

[Objective]High yield xylanase strains were found by screening with ultraviolet mutagenesis of Chaetomium globosum protoplast.[Methods]Chaetomium globosum AS3.3601 protoplasts were prepared under different conditions.The effect of different parameters such as enzyme concentration,temperature and time on protoplast production and regeneration rate was analyzed.The dose of UV mutagenesis was determined by single factor experiments.Xylanase activity was measured by DNS methods after initial screening and rescreening.[Results]Judged by combined conditions considering production rate and regeneration rate of protoplasm,the best conditions for preparing protoplast was at enzyme concentration of 1.5%,reaction temperature of 30℃,and time of 4h.The protoplasts treated with 60s of UV irradiation show a xylanase activity of 9980 IU /mL.[Conclusion]xylanase activity of YZ-8 with mutation strain increased 92.6% compared with the original strain and it is genetically stability.